Multiple-screw lifting jack



April 22 1924. 1,491,082

J. COR'YELL MULTIPLE SCREW LIFTING JACK Filed Oct. 4, 3.922

" Latimu v and .16 it'll bear- 18 between the To 1252 whom 'E" I J m1 citizw 0f the 1 with a Yadia 1i Detroit, in rests on thrust bearii -Miaflffilichigam 1" and cnmmfervntial in 2.01%, 0f 1 0 U11; flange 61'' the Hm mm; is them .1;; and (no upward mallsfc-n'ed to the my than hih'mugh dis 21210 "x; nl'igln height jzz V This invonayirn is of a puiesizel and 11 pair 0? screws mwin the pedestal me Iii-W bcinr i ngi gwiinaiiy big vvithij.

n "with imlgzitudina Rugs 1 in ihe inner loi'lg itndinnl grooves 2? in the hoilow miter sm' w 4; and thus the inns-1 SCJ'CW from turning Live is *ihe outer,

the at} ifhe wing; :9 inner sc'rm' can be moved iongi tbreadw inner ssrew tui imajly upwardEy n'emrl its own igngth hen: wmed i 011.2; 0'? *2 ier screw and the outer screw can .6 upwardly marly its 1631 a} if w lknvs xihat the ustimce $21 3 m1 is nearly twins he a1 heigh; of iiS cap.

519 i uior 3 cap 26 will be Ga sum 0f the thwmds of the two 3501" ash tnin of 1m bevel gear 5. Q of th s "CWO say-4m both '1 "he tuai pitches at imnllefli handed, i' mfi" "be the distance 1311 2 cap practice, I prefer "to have nth. SLHHY'E fight handed.

011i the inner :em'mv from 'apax'm-C tan fin and the lugs with Una nut 19. I pre- "a at the points 29. ppm for the in ml in the outer h 1- J M1 the cpcmting; device mp of UM! outer screw, it

4, 00m: led 0 any 1113111111 01' power awed inf: meow P62 Bertie? 01' :2; ion 0? this SCE'QW unism to ummy MTV flesnm mmuma't-unyof pans so Yong as it wnpie ed for bxe'rting pressure 101i- 0n the upper side 01 the gitudinzs "-01%" the aclgews. 5 -s thrust bearing, sLown 0 cnnsisi The (31., 11a; of comm-lemon and the pro portionsof the ports of this lifting jock may, however, be chen retl by those skilled in the art without (ieie 11;; from the spurt of my invention as set forth in the following claims.

1. .ln a, lifting jack, a pedestal embodying a nut, a screw. mounted therein, means to rotate the screw, a nut mount l on the screw, :1 second screw mounted in said nut, means to prevent the out from rotating, and means to c: use the second screw to turn with the first.

In a lifting; jack, 2: peestei. embodying 1:, out, a, screw mounted therein, a nut nioui'itecl on the "row, second screw.

mounted in the second. out and, rotatable with the first screw, and means to rotate the screw relative to the nuts.

3. In a lifting flick, pedesml embodying a not, a hollow screw mounted therein, s not mounted on the screw, second sore-v. in said second nut and sl'ulable in the hollow screw and rotelehle therewith, means to rotote the screws, and means topreveut the second out from turning.

1n n lifting junk, a pedestal embodying n nut, a hollow screw mounted therein, e nut mounted. on the screw, :1 SCL'Olltl screw extending centrally within the hollow sir-rel: and mounted in the not carried thereby, gears to rotate the hollow screw in sni' pedestal, and means lo prevent the nutsup ported by the hollow screw from turning.

5. In a. lifting jucli, a pedestal embodying a nut, a hollow screw mounted therein, a nut mounted on the screw, a second screw extending centi "ly within lhe hollow screw and mounted in the nut curried "il'ioreh y, to rotate the hollow screw in salisl pedestal, and means to prevent the nut sup" l-ewes tached to the nut lil'ltl lnwin it DllllCLl c0 nootion uilh he! istul and a foot-liftattached to said housing.

7. In device of the character (lescribeu, the combination ole, pair of telescoping siren ""etionury iithe outer screw, :1- l'iOlllOliilljllli a not for the inner screw mounted on fire outer screw, and means to rotate the two sore 8.351 a device 01 "he character described, the combination of pair of telescoping screws, :1 st: iouei not for the outer screw, e. non-rotatul le .ut for. the inne screw mounted on tie outer screw, and means to rotate the two screw iultaneously and in tln some direction:

2). In loinl li ing}; device, the combinetion of a support en'ilioclying a nut, a screw mounted in the nut, e not carried by said screw, :1 second screw mounted in the secoul'l nut and adapted to engage the load and rotatable with the first screw, rind means to reaatiie ition hetwee the screws JQHN CORYELL. 

